The invention relates to a dispensing device for dispensing an active-substance fluid into the flushing liquid in a toilet bowl. The term active-substance fluid denotes free-flowing, that is to say liquid to viscous active-substance preparations, possibly ones which are gel-like or also paste-like or granular or pourable in some other way, with cleaning, disinfecting, deodorizing, bleaching and similar actions (described, in particular, in DE 199 30 362 A1, and in EP 0 775 741 A1 and EP 0 960 984 A2).
Various configurations of dispensing devices of the type in question in the form of basket-like WC units are known. In the first place, dispensing devices for a single active-substance fluid are known. The active-substance fluid is located there in a supply container which is arranged firmly, or inserted in an exchangeable manner, in a holder and has an outlet opening arranged on the base side when the supply container is fitted on the holder.
In the case of a first known dispensing device for a single active-substance fluid, the active-substance fluid is added via an actuating element which can be impregnated therewith and can be exposed to the action of the flushing liquid (e.g. an actuating element made of an open-cell foam) (EP 785 315 A1). In this case, the outlet opening of the supply container, once a closure part of the supply container has been pushed out, is largely closed by a sealing element arranged in a stationary manner on the holder, with the result that just a flow path of small cross section is available in order for the active-substance fluid to trickle out. The device functions by utilizing the capillary action of the open-cell foam.
A dispensing device which is similar to the dispensing device explained above and has as ribbed plate serving for distributing the active-substance fluid in the flushing liquid is also known (DE 199 12 217 A1; WO 99/66140 A). In the case of this design, the supply container has an outlet opening which is enclosed by an annular border and via which the active-substance fluid can be dispensed into the flushing liquid. A plate-like distributing element is provided on the holder, this distributing element, on the one hand, having a region of action over which flushing liquid flows during the flushing operation and, on the other hand, a connection region, in which a piercing spike is arranged. The interior of the supply container is connected permanently to the distributing element via the outlet opening, with the interposition of the opening spike with lateral ribs, which prevents free flowing active-substance fluid. For this purpose, the border of the outlet opening is spaced apart by a small distance from the surface of the distributing element. A spacer arrangement is provided in order to realize this distance, the spacer arrangement having parallel ribs which form depressions between them. These depressions extend from the connection region into the region of action, as far as the opposite border, and serve, in the region of action, for distributing the active-substance fluid into the flushing liquid.
A further such dispensing device is described in the international publication WO 01/44591 A1. In the case of this design, the distributing element has on the top side, on that side of the point of connection which is directed away from the region of action, a ventilating channel which extends through beneath the border from the longitudinal border of the distributing element and is open on the top side.
GB 2 338 496 A describes a dispensing device which is ventilated by an additional valve. Different variants are illustrated for the functioning of this valve, but the valve opening is arranged separately from the outlet opening.
In the case of all the dispensing devices which are known from the prior art, provision has to be made for the active-substance fluid which passes out of the supply container somehow to be replaced by air flowing into the supply container. Ventilating channels which extend beneath the outlet opening of the supply container are regularly realized in the prior art. This results in a dynamic interaction of viscous active-substance fluid and air, as a result of which the exchange of air is ensured.
The teaching is based on the problem of optimizing the known dispensing device, for dispensing active-substance fluids, in respect of possible control of the operation of dispensing the active-substance fluid. The basic elements of known dispensing devices for dispensing an active-substance fluid into the flushing liquid in a toilet bowl include a supply container (2) for an active-substance fluid, the supply container (2) having an outlet-side border (3) and an outlet opening (4) via which the active-substance fluid can be dispensed into the flushing liquid. A plate-like distributing element (6) is provided, this having, on the one hand, a region of action (7) over which flushing liquid flows during the flushing operation and, on the other hand, a connection region (8), in which a point of connection (9) for the outlet opening (4) of the supply container (2) is arranged. The interior of the supply container (2) is connected permanently to the distributing element (6) via the outlet opening (4), and that, for this purpose, the border (3) is spaced apart by a small distance from the surface of the distributing element (6). Arranged on the top side of the distributing element (6), on that side of the point of connection (9) which is directed away from the region of action (7), is a ventilating channel (12) which extends through beneath the border (3) from the longitudinal border of the distributing element (6) and is open on the top side.